On 03/03/2017 04:35 PM, Olivier Swinkels wrote: > Hi, > > I'm in quite a pickle here. I can't recover from a disk failure on my > 6 disk raid 5 array. > Any help would really be appreciated! > > Please bear with me as I lay out the the steps that got me here: [trim /] Well, you've learned that mdadm --create is not a good idea. /-: However, you did save your pre-re-create --examine reports, and it looks like you've reconstructed correctly. (Very brief look.) However, you discovered that mdadm's defaults have long since changed to v1.2 superblock, 512k chunks, bitmaps, and a substantially different metadata layout. In fact, I'm certain your LVM metadata has been damaged by the brief existence of mdadm's v1.2 metadata on your member devices. Including removal of the LVM magic signature. What you need is a backup of your lvm configuration, which is commonly available in /etc/ of an install, but naturally not available if /etc/ was inside this array. In addition, though, LVM generally writes multiple copies of this backup in its metadata. And that is likely still there, near the beginning of your array. You should hexdump the first several megabytes of your array looking for LVM's XML formatted configuration. If you can locate some of those copies, you can probably use dd to extract a copy to a file, then use that with LVM's recovery tools to re-establish all of your LVs. There is a possibilility that some of your actual LV content was damaged by the mdadm v1.2 metadata, too, but first recover the LVM setup. Phil -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
